libraries/grab_globals.lib.php

   1 <?php
   2 /* $Id$ */
   3 // vim: expandtab sw=4 ts=4 sts=4:
   4
   5
   6 /**
   7  * This library grabs the names and values of the variables sent or posted to a
   8  * script in the $_* arrays and sets simple globals variables from them. It does
   9  * the same work for the $PHP_SELF, $HTTP_ACCEPT_LANGUAGE and
  10  * $HTTP_AUTHORIZATION variables.
  11  *
  12  * loic1 - 2001/25/11: use the new globals arrays defined with php 4.1+
  13  */
  14
  15 // just to be sure there was no import (registering) before here
  16 $variables_whitelist = array (
  17     'GLOBALS',
  18     '_SERVER',
  19     '_GET',
  20     '_POST',
  21     '_REQUEST',
  22     '_FILES',
  23     '_ENV',
  24     '_COOKIE',
  25 );
  26
  27 foreach ( get_defined_vars() as $key => $value ) {
  28     if ( ! in_array( $key, $variables_whitelist )  ) {
  29         unset( $$key );
  30     }
  31 }
  32 unset( $key, $value );
  33
  34 // protect against older PHP versions' bug about GLOBALS overwrite
  35 // (no need to translate this one :) )
  36 // but what if script.php?GLOABLS[admin]=1&GLOBALS[_REQUEST]=1 ???
  37 if ( isset( $_REQUEST['GLOBALS'] ) || isset( $_FILES['GLOBALS'] )
  38   || isset( $_SERVER['GLOBALS'] ) || isset( $_COOKIE['GLOBALS'] )
  39   || isset( $_ENV['GLOBALS'] ) ) {
  40     die( 'GLOBALS overwrite attempt' );
  41 }
  42
  43 require_once './libraries/session.inc.php';
  44
  45 /**
  46  * @var array $import_blacklist variable names that should NEVER be imported
  47  *                              from superglobals
  48  */
  49 $import_blacklist = array(
  50     '/^cfg$/i',      // PMA configuration
  51     '/^GLOBALS$/i',  // the global scope
  52     '/^str.*$/i',    // PMA strings
  53     '/^_.*$/i',      // PMA does not use variables starting with _ from extern
  54     '/^.*\s+.*$/i',  // no whitespaces anywhere
  55     '/^[0-9]+.*$/i', // numeric variable names
  56     //'/^PMA_.*$/i',   // other PMA variables
  57 );
  58
  59 /**
  60  * copy values from one array to another, usally from a superglobal into $GLOBALS
  61  *
  62  * @uses    $GLOBALS['import_blacklist']
  63  * @uses    preg_replace()
  64  * @uses    array_keys()
  65  * @uses    array_unique()
  66  * @uses    get_magic_quotes_gpc()  to check wether stripslashes or not
  67  * @uses    stripslashes()
  68  * @param   array   $array      values from
  69  * @param   array   $target     values to
  70  * @param   boolean $sanitize   prevent importing key names in $import_blacklist
  71  */
  72 function PMA_gpc_extract($array, &$target, $sanitize = TRUE) {
  73     if (!is_array($array)) {
  74         return FALSE;
  75     }
  76
  77     if ( $sanitize ) {
  78         $valid_variables = preg_replace( $GLOBALS['import_blacklist'], '',
  79             array_keys( $array ) );
  80         $valid_variables = array_unique( $valid_variables );
  81     } else {
  82         $valid_variables = array_keys( $array );
  83     }
  84
  85     $is_magic_quotes = get_magic_quotes_gpc();
  86
  87     foreach ( $valid_variables as $key ) {
  88
  89         if ( strlen( $key ) === 0 ) {
  90             continue;
  91         }
  92
  93         if ( is_array( $array[$key] ) ) {
  94             // there could be a variable coming from a cookie of
  95             // another application, with the same name as this array
  96             unset($target[$key]);
  97
  98             PMA_gpc_extract($array[$key], $target[$key], FALSE);
  99         } elseif ($is_magic_quotes) {
 100             $target[$key] = stripslashes($array[$key]);
 101         } else {
 102             $target[$key] = $array[$key];
 103         }
 104     }
 105     return TRUE;
 106 }
 107
 108
 109 // check if a subform is submitted
 110 $__redirect = NULL;
 111 if ( isset( $_POST['usesubform'] ) ) {
 112     // if a subform is present and should be used
 113     // the rest of the form is deprecated
 114     $subform_id = key( $_POST['usesubform'] );
 115     $subform    = $_POST['subform'][$subform_id];
 116     $_POST      = $subform;
 117     if ( isset( $_POST['redirect'] )
 118       && $_POST['redirect'] != basename( $_SERVER['PHP_SELF'] ) ) {
 119         $__redirect = $_POST['redirect'];
 120         unset( $_POST['redirect'] );
 121     } // end if ( isset( $_POST['redirect'] ) )
 122     unset( $subform_id, $subform );
 123 } // end if ( isset( $_POST['usesubform'] ) )
 124 // end check if a subform is submitted
 125
 126 if (!empty($_GET)) {
 127     PMA_gpc_extract($_GET, $GLOBALS);
 128 } // end if
 129
 130 if (!empty($_POST)) {
 131     PMA_gpc_extract($_POST, $GLOBALS);
 132 } // end if (!empty($_POST))
 133
 134 if (!empty($_FILES)) {
 135     foreach ($_FILES AS $name => $value) {
 136         $$name = $value['tmp_name'];
 137         ${$name . '_name'} = $value['name'];
 138     }
 139 } // end if
 140 unset( $name, $value );
 141
 142 if (!empty($_SERVER)) {
 143     $server_vars = array('PHP_SELF', 'HTTP_ACCEPT_LANGUAGE', 'HTTP_AUTHORIZATION');
 144     foreach ( $server_vars as $current ) {
 145         // its not important HOW we detect html tags
 146         // its more important to prevent XSS
 147         // so its not important if we result in an invalid string,
 148         // its even better than a XSS capable string
 149         if ( isset( $_SERVER[$current] ) && false === strpos( $_SERVER[$current], '<' ) ) {
 150             $$current = $_SERVER[$current];
 151         // already importet by register_globals?
 152         } elseif ( ! isset( $$current ) || false !== strpos( $$current, '<' ) ) {
 153             $$current = '';
 154         }
 155     }
 156     unset( $server_vars, $current );
 157 } // end if
 158
 159 // Security fix: disallow accessing serious server files via "?goto="
 160 if (isset($goto) && strpos(' ' . $goto, '/') > 0 && substr($goto, 0, 2) != './') {
 161     unset($goto);
 162 } // end if
 163
 164 unset( $import_blacklist );
 165
 166 if ( ! empty( $__redirect ) ) {
 167     // TODO: ensure that PMA_securePath() is defined and available
 168     // for this script. Meanwhile we duplicate what this function does:
 169     require('./' . preg_replace('@\.\.*@','.',$__redirect));
 170     exit();
 171 } // end if ( ! empty( $__redirect ) )
 172 ?>